Harvard philosophy professor Cavell -- an empathic Thoreau scholar -- views Walden as a ""heroic writing, a nation's scripture"" in which the hero is a paradoxical prophet who answers the imperative of the relation of writer and society at once in terms of ""absolute hope and yet of absolute defeat, his own and his nation's."" Underlying this apparent sense of ambivalence, says Cavell, is the notion of ""integrity conceived as an activity"" -- Thoreau's Walden, a testament to discovery and dissent, to the civilizing sense of actively ""placing ourselves in the world."" Cavell examines the coalescing dualisms of distance and presence, writer and reader, hope and despair, myth and nature before Thoreau's fact, as revealed in a book which is not a substitute for life but a ""prosecution of it."" ""The writer's sentences must at each point come to an edge. He has at all times to know simultaneously the detail of what is happening and what it means to him that it happens so."" A concluding section treats Thoreau's philosophy as a legitimate Kantian extension in which the objects of knowledge require -- in a modern terminology -- ""grammatical or phenomenological preparation. . . . What we have constructed is fate itself."" For a special few, a special event.